The present invention relates to a proton source incorporating a cyclotron. Cyclotrons are devices for accelerating a beam of ionized particles around a substantially spiral path lying normal to an axial magnetic field, so as to produce a continuous output beam of particles at the high energy levels required for research and other purposes involving ion bombardment.
In a cyclotron, a beam of ionized particles travels past accelerating electrodes which are paired to have opposing electrical voltages applied to them. With each transition of the ionized particles past the differential voltage of a pair of electrodes, the particles gain energy. The voltages applied to the electrodes are alternating voltages of radio frequency and are applied at a frequency synchronized with the transitions of the ionized particles. By causing the ionized particles to travel in a roughly circular path which lies normal to an axial magnetic field, the particles can be made to make numerous transitions past a small number of electrode pairs receiving acceleration and gaining in radius at each transition.
The present invention addresses the problem of using the cyclotron to produce a high current pulsed proton beam either to inject into another accelerator to give higher energies, or to provide an intense pulsed source of neutrons.